Flip-chip bonding is a well-known and mature chip bonding technology where a plurality of bumps are disposed on a chip, then bonded on the corresponding connecting pads of a substrate without extra wire-bonding space to meet the requirements of miniaturization and high-density I/O. However, the conventional wire bonding technology can change the pin assignment of a chip through bonding options. But the interconnection between flip-chip bumps and corresponding bonding pads are point-to-point connections which are fixed during flip-chip bonding processes so that pin assignment of a chip can not be changed. When a semiconductor device with different pin assignment is fabricated, the only solution is to redesign the substrate circuitry.